it's very depressing because I think it's too late to invest in a great invention that comes out maybe once in a thousand years.
Don't get depressed. Many of us here have heard Bitcoin earlier than you but did we give up? No. We also thought the same thing as you but it was never too late for anyone to invest. Are you thinking that your $100 might not be enough? Because it isn't enough if you're going to take a look at the market price and it's unlikely that we're going to see it that low because of the movement that it has got from few years ago and with halvings and many adoptions that happened, you have to consider its growth.
Their is no late time time for you to invest in bitcoin, even at the price which bitcoin is currently is , it is not a bad idea to buy bitcoin because we are entering the bull market, but wellif one feels and doesn't have the mind or understanding to buy now they shouldn't force themselves to invest because even if they dont have the believe that it is right to buy now just because of bitcoin price has increased to this current price they may still not have the patience to hodl to the investment.
It's not that bad to buy right now and we always say that regardless of the market condition because we've got our long term visions and plans for Bitcoin. Having that said, if you're someone who has that long term plans to hold it then there's no problem if you buy right now because the halving is coming and we know what will be next about that. Just don't force yourself to invest when you can't really afford it but if time permits you to, don't waste that opportunity.